Towards Harnessing Relay Mobility in MANETs
Rohit Naini, Pierre Moulin - University of Illinois, Urbana-Champaign
Relay Channel as part of a MANET
Mutually Interfering Relay Channels
- The relay channel with single interferer though a good starting point , yields simplistic solutions.
- An actual Adhoc Network could potentially have several interfering transmissions.
Locations Should be Jointly Optimized
- Sensors measure
- user activity
- Convert activities
- to calories burnt
Compress and Forward rate vs Relay Position
Calculations Log on PDA
- Mobility should be viewed as a resource in an Adhoc Network
- Exploring the potential held by mobility in a Relay Channel can provide valuable insights for larger networks
- This problem introduces aspects such as inter-nodal cooperation in different parts of the network.
- The joint-mobility of several nodes entitles a multiple objectives game-theoretic approach.
- Solving this problem would give valuable insight into interaction between coexistent non-cooperating network blocks
Relay Position- Angular
Relay Position radial
- The transmissions from rest of the network are assumed to be from unknown Gaussian codebooks
- Correlation between noises at Relay and Destination are computed based on Relay position with respect to the position of interfering nodes.
- The throughputs of the three relay schemes are evaluated by varying the relay location
Interferer Locations –
Relay Channel with Single Interferer
- Relay Channel capacity is unknown but surrogate performance metrics can be used:
- Cut-set Bound
- Decode-Forward Rate
- Compress Forward Rate
- A Gaussian Channel model is employed with a corrected quadratic path loss
- External Interferer emits Gaussian signal with an unknown codebook
- Subject to mobility restrictions, optimal relay location/scheme can be chosen
Conclusion and Future Directions
Simulation Analysis and Discussion
- Interference management holds the key to improving Adhoc Network performance
- Mobility can be used to minimize the malicious impact of interference between the different parts of the network
- The usually sub-optimal Compress-Forward scheme proves helpful in a system marred with a high degree of interference
- Future Directions
- Understand the role of mobility in other adhoc network blocks.
- Devise mobility strategies for cooperative multi-hop relaying
- The optimal relay locations vary significantly based on the scheme being used
- For a Decode-Forward scheme, it is optimal for the relay to relocate itself away from the Interfering nodes
- For a Compress-Forward scheme, relay should relocate itself to a point with higher interference reception and good correlation to Destination’s Noise
- Compress-Forward scheme exploits the noise correlation to allow cooperation between the Relay and Destination
- Compress-Forward is well suited when there is a relatively close interfering node with high power
Node Polar Co-ords
Cut Set Bound